ANXA1-derived peptide for targeting PD-L1 degradation inhibits tumor immune evasion in multiple cancers

Abstract

BackgroundImmune checkpoint inhibitors (ICIs) therapy targeting programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) shows promising clinical benefits. However, the relatively low response rate highlights the need to develop an alternative strategy to target PD-1/PD-L1 immune checkpoint. Our study focuses on the role and mechanism of annexin A1 (ANXA1)-derived peptide A11 degrading PD-L1 and the effect of A11 on tumor immune evasion in multiple cancers.MethodsBinding of A11 to PD-L1 was identified by biotin pull-down coupled with mass spectrometry analysis. USP7 as PD-L1’s deubiquitinase was found by screening a human deubiquitinase cDNA library. The role and mechanism of A11 competing with USP7 to degrade PD-L1 were analyzed. The capability to enhance the T cell-mediated tumor cell killing activity and antitumor effect of A11 via suppressing tumor immune evasion were investigated. The synergistic antitumor effect of A11 and PD-L1 mAb (monoclonal antibody) via suppressing tumor immune evasion were also studied in mice. The expression and clinical significance of USP7 and PD-L1 in cancer tissues were evaluated by immunohistochemistry.ResultsA11 decreases PD-L1 protein stability and levels by ubiquitin proteasome pathway in breast cancer, lung cancer and melanoma cells. Mechanistically, A11 competes with PD-L1’s deubiquitinase USP7 for binding PD-L1, and then degrades PD-L1 by inhibiting USP7-mediated PD-L1 deubiquitination. Functionally, A11 promotes T cell ability of killing cancer cells in vitro, inhibits tumor immune evasion in mice via increasing the population and activation of CD8+T cells in tumor microenvironment, and A11 and PD-1 mAb possess synergistic antitumor effect in mice. Moreover, expression levels of both USP7 and PD-L1 are significantly higher in breast cancer, non-small cell lung cancer and skin melanoma tissues than those in their corresponding normal tissues and are positively correlated in cancer tissues, and both proteins for predicting efficacy of PD-1 mAb immunotherapy and patient prognosis are superior to individual protein.ConclusionOur results reveal that A11 competes with USP7 to bind and degrade PD-L1 in cancer cells, A11 exhibits obvious antitumor effects and synergistic antitumor activity with PD-1 mAb via inhibiting tumor immune evasion and A11 can serve as an alternative strategy for ICIs therapy in multiple cancers.

SP1‐activated USP27X‐AS1 promotes hepatocellular carcinoma progression via USP7‐mediated AKT stabilisation

“…USP7 regulates the function and turnover of a wide range of substrates, including P53, ERK1/2, PD-L1, PRMT5, ANXA1, STAT3 and ECT2, which are crucial components of numerous oncogenic signalling pathways. [46][47][48][49][50][51][52] For example, USP7 is a crucial deubiquitinase needed to stabilise oncogenic versions of DDX3X. By stabilising DDX3X, USP7 increases Wnt/beta-catenin signalling, which has previously been demonstrated to be strongly correlated with colorectal cancer cell invasiveness.…”

“…Deubiquitylases have been implicated with a number of cancers, including HCC, according to recent research. USP7 regulates the function and turnover of a wide range of substrates, including P53, ERK1/2, PD‐L1, PRMT5, ANXA1, STAT3 and ECT2, which are crucial components of numerous oncogenic signalling pathways 46–52 . For example, USP7 is a crucial deubiquitinase needed to stabilise oncogenic versions of DDX3X.…”

Inhibition of CK2/ING4 Pathway Facilitates Non‐Small Cell Lung Cancer Immunotherapy

“…[14] Induction of PD-L1 degradation in proteasome is triggered by E3 ubiquitin ligases such as Cullin3, SPOP [25] STUB1, [26] 𝛽-TrCP, [27] RNF125, [28] ITCH, [29] ariadne RBR E3 ubiquitin protein ligase 1 (ARIH1), [30] membrane-associated RING-CH 8 (MARCH8), [31] and HRD1. [32] Furthermore, PD-L1 degradation in proteasome could be caused by albendazole/ubiquilin 4 pathway, [33] annexin A1 -derived peptide A11/USP7 pathway, [34] and ISG15 ubiquitin-like protein. [35] In addition to proteasomal-dependent degradation, PD-L1 could be degradation in lysosome by different pathways such as PKC𝛼/GSK3𝛽/MITF, [36,37] SA-49/PKC𝛼/GSK3𝛽/MITF, [38] IPAG/Sigma-1, [39] MTSS1/AIP4, [40] TBM-1/mTORC1/TFEB, [41] and amlodipine/calcium flux.…”

Emerging therapeutic frontiers in cancer: insights into posttranslational modifications of PD-1/PD-L1 and regulatory pathways

“…In pancreatic cancer, USP8 inhibits the ubiquitination-regulated proteasome degradation pathway by positively interacting with PD-L1 and upregulating its expression [ 81 ]. USP7 mediates the ubiquitination of PD-L1 and inhibits its degradation [ 82 ]. Additionally, UCHL1 promotes PD-L1 deubiquitination and upregulates its expression in NSCLC [ 83 ].…”

“…Similarly, a study on a USP8 inhibitor demonstrated its effectiveness in suppressing pancreatic tumor growth by activating killer T cells, especially when combined with anti-PD-L1 therapy [ 81 ]. Additionally, A11, an inhibitor of USP7, showed promising antitumor effects by blocking PD-L1’s ability to help tumors evade immune detection, and when combined with PD-1 antibody therapy, it showed enhanced antitumor activity [ 82 ]. Additionally, the application of the CSN5 inhibitor curcumin inhibited the ubiquitination of PD-L1, reduced PD-L1 expression, and increased the sensitivity of tumor cells to CTLA4 immunotherapy [ 73 ].…”